Linked Life Data

17499996

Source:http://linkedlifedata.com/resource/pubmed/id/17499996

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2007-6-12
pubmed:abstractText
The secretory isozyme of human carbonic anhydrase (hCA, EC 4.2.1.1), hCA VI, has been cloned, expressed, and purified in a bacterial expression system. The kinetic parameters for the CO(2) hydration reaction proved hCA VI to possess a k(cat) of 3.4 x 10(5)s(-1) and k(cat)/K(M) of 4.9 x 10(7)M(-1)s(-1) (at pH 7.5 and 20 degrees C). hCA VI has a significant catalytic activity for the physiological reaction, of the same order of magnitude as the ubiquitous isoform CA I or the transmembrane, tumor-associated isozyme CA IX. A series of amino acids and amines were shown to act as CA VI activators, with variable efficacies. l-His, l-Trp, and dopamine showed weak CA VI activating effects (K(A)s in the range of 21-42 microM), whereas d-His, d-Phe, l-DOPA, l-Trp, serotonin, and some pyridyl-alkylamines were better activators, with K(A)s in the range of 13-19 microM. The best CA VI activators were l-Phe, d-DOPA, l-Tyr, 4-amino-l-Phe, and histamine, with K(A)s in the range of 1.23-9.31 microM. All these activators enhance k(cat), having no effect on K(M), participating thus in the rate determining step in the catalytic cycle, the proton transfer reactions between the enzyme active site and the environment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0968-0896
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5351-7
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Carbonic anhydrase activators: the first activation study of the human secretory isoform VI with amino acids and amines.
pubmed:affiliation
Department of Gastroenterology and Hepatology, Kochi Medical School, Nankoku, Kochi, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't